High torque catheter possessing multi-directional deflectability and methods thereof

ABSTRACT

A flexible catheter shaft suitable for inserting into a body of a patient comprising a deflectable, high torque transmission assembly of a slit tubular element that has either a plurality of rows of slits with anchors or at least one continuously spiraling slit on said slit tubular element and has sufficient bending and torque properties ensuring that a substantial fraction of the bending, rotational and displacement forces provided along said flexible catheter shaft are translated to bending, rotational and displacement forces at a distal end of said flexible catheter shaft.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/372,484 filed on Aug. 12, 1999, now U.S. Pat.No. 6,246,914.

FIELD OF THE INVENTION

[0002] The present invention generally relates to improved constructionsfor a deflectable, high torque catheter. More particularly, thisinvention relates to methods and catheters for diagnosing and treatingcardiac arrhythmias via a multi-directional, deflectable, torquetransmittable cardiovascular catheter by mapping and stimulating thehuman heart with pacing, cardioversion, defibrillation, and/orradiofrequency ablation therapy.

BACKGROUND OF THE INVENTION

[0003] Symptoms of abnormal heart rhythms are generally referred to ascardiac arrhythmias, with an abnormally rapid heart beat being referredto as tachycardia. The present invention is concerned with the treatmentof tachycardias that are frequently caused by the presence of an“arrhythmogenic site” or “accessory atrioventricular pathway” close tothe surface of the upper chambers of a heart. The heart includes anumber of normal pathways that are responsible for the propagation ofelectrical signals from the upper chamber to the lower chamber necessaryfor performing normal systole and diastole functions. The presence ofarrhythmogenic site or accessory pathway can bypass or short circuit thenormal pathway, potentially resulting in very rapid heart contractions,referred to here as tachycardias.

[0004] Treatment of tachycardias may be accomplished by a variety ofapproaches, including drugs, surgery, implantablepacemakers/defibrillators, and catheter ablation. Catheter basedradiofrequency ablation is generally performed after conducting aninitial electrophysiology study where the locations of thearrhythmogenic site and/or accessory pathway are determined.Electrophysiology study and temporary defibrillator/cardioverter involvecatheters having at least one electrode means for the delivery of lowenergy pacing pulses directly to the heart tissue at various intervalsor frequencies in order to induce the arrhythmia. Once the arrhythmia isinduced, it must be terminated by typically delivering a high-energydefibrillation shock across the patient's chest with paddles. A specificvery high therapeutic voltage is required within the heart to terminatethe induced arrhythmias. The voltage delivered through a conventionaltransthoracic defibrillator paddle from outside the body issubstantially greater than the necessary therapeutic voltage because itneeds to compensate for the energy losses through the skin and thethoracic cavity. An internal defibrillator/cardioverter from a catheterposes less risk and higher therapeutic efficiency.

[0005] A transvenous catheter that combines the functions of the ratesensing, pacing, and defibrillation has a plurality of electrodes on adistal portion. The catheter should have multi-directionaldeflectability and high torque so that it can be guided to the exactlocation of the heart tissue for pacing, cardioversion, defibrillationand/or radiofrequency ablation. The catheter should also be flexibleenough for insertion into a body and have adequate surface forcontacting the intracardiac tissues. Some examples of cardioverter andmethods are U.S. Pat. No. 5,005,587 to Scott, U.S. Pat. No. 5,766,224 toAlferness et al., U.S. Pat. No. 5,814,081 to Ayers et al., U.S. Pat. No.5,810,887 to Accorti, Jr. et al., and U.S. Pat. No. 5,913,887 to Michel.Because of the exact location requirements, the deflectability andtorque transmission properties of a catheter to ensure that asubstantial fraction of the rotational and displacement forces providedalong the catheter are translated to rotational and displacement forcesat the distal end of said catheter become very important.

[0006] Another particular interest point to the present invention isradiofrequency (RF) ablation protocols that have proven to be highlyeffective in tachycardia treatment while exposing a patient to minimalside effects and risks. After a mapping study, an ablation catheter isusually introduced to the target heart chamber and is manipulated sothat the ablation tip electrode lies exactly at the target tissue site.Radiofrequency energy or other suitable energy is then applied throughthe electrode to the cardiac tissue in order to ablate the tissue ofarrhythmogenic site or the accessory pathway. By successfully destroyingthat tissue, the abnormal conducted signal patterns responsible for thetachycardia can be eliminated. In the case of atrial fibrillation(AFib), multiple arrhythmogenic sites and/or multiple accessory pathwaysexist. It becomes desirable that a long linear lesion or a broad lesionzone at the tissue contact sites to ensure appropriate energy delivery.

[0007] Scott in U.S. Pat. No. 5,005,587 discloses a braided electrodelead in an endocardial pacing and defibrillation catheter having anelongated hollow polyurethane shaft. Although providing good stiffnessand biocompatibility, the polyurethane tube lacks sufficient translationbetween the rotational and displacement forces applied along the body ofthe polyurethane tube. Accorti Jr. et al. in U.S. Pat. No. 5,810,887discloses a catheter having a braided wire section for torquetransmission. For the purposes of cardioversion and defibrillation, thesurface contact area becomes very critical. With regards to the braidedwire section, only the outer radial surface of the braided section isemployed in contacting a tissue. In other words, the effectivetissue-contacting surface of wires in the braided wire section issub-optimal as compared to an essentially flat surface. The braiding ofwires also makes the braided wire section undesirably rigid.

[0008] Similarly, Michel in U.S. Pat. No. 5,913,887 discloses atransvenous device having three coil electrodes for cardioversion ofatrial flutter or atrial fibrillation. The tissue-contacting surfacearea of a coil electrode is less than an essentially flat surface. Thecoil electrode also suffers a drawback of less torque transmissionproperty. None of the conventional temporary catheters forcardioversion/defibrillation has a steerability property.

[0009] While cardioversion and defibrillation procedures using anexisting catheter design have produced some promising results, thebending and torque transmission properties, the effectivetissue-contacting surfaces, and rigidity of a conventional catheterusually do not meet the clinical requirements. Therefore, there is anurgent clinical need to have a flexible catheter that also possessmulti-directional deflectablility and high torque transmitting propertyto be used in cardioversion and defibrillation procedures.

SUMMARY OF THE INVENTION

[0010] The present invention provides an improved deflectable and hightorque catheter that can be used in the procedures of stimulating thehuman heart with pacing, cardioversion, defibrillation and/orradiofrequency ablation therapy. It is one object of the presentinvention to provide a flexible catheter with high torque transmissionproperties. It is another object of the present invention to provide aflexible catheter with a slit tubular element that has a plurality ofrows of slits and anchors on said slit tubular element. It is stillanother object of the present invention to provide a flexible catheterwith a slit tubular element that has at least one continuously spiralingslit with longitudinal rows of anchors on said slit tubular element. Theword “slit” is defined as a straight or curved narrow cut or opening ona substrate in this patent application.

[0011] In one embodiment, a deflectable, high torque catheter comprisesa flexible catheter shaft having a distal shaft section, a proximalshaft section and at least one middle shaft section, wherein each shaftsection has a distal end and a proximal end, and wherein the shaftsection is secured to its adjacent shaft section, said flexible cathetershaft having at least one lumen extending between the distal end of thedistal shaft section and the proximal end of the proximal shaft section.A handle may be secured at the proximal end of the proximal shaftsection. The catheter further comprises at least one shaft sectioncomprising a deflectable, high torque transmission assembly fortransmitting deflectability and torque along said at least one shaftsection, said deflectable and high torque transmission assemblycomprising a slit tubular element that has a plurality of staggered rowsof slits and anchors on said slit tubular element and has sufficientdeflectability and torque properties ensuring that a substantialfraction of the rotational, displacement, and bending forces providedalong said at least one shaft section are translated to rotational,displacement, and bending forces at the distal end of said shaft sectionof the flexible catheter shaft. The deflectable, high torque catheter ofthe present invention is equally useful as either a non-energy deliverycatheter or an energy delivery catheter.

[0012] In another embodiment, said deflectable and high torquetransmission assembly comprises a slit tubular element that has at leastone continuously spiraling slit on said slit tubular element and hassufficient bending and torque properties ensuring that a substantialfraction of the rotational, displacement, and bending forces providedalong said at least one shaft section are translated to rotational,displacement, and bending forces at the distal end of said shaft sectionof the flexible catheter shaft, wherein the slit tubular element has aplurality of parallel, staggered rows of slit members and anchorsresulting from the at least one continuously spiraling slit.

[0013] In a preferred embodiment, the arrangement of said plurality ofstaggered rows of slits with respect to a longitudinal axis of saidshaft section of the catheter may be selected from the group consistingof a perpendicular slit, an angled slit, a curved slit, and acombination of the above thereof Furthermore, each of the plurality ofslits has a slit starting point at an outer surface of said shaftsection and two slit terminating points at said outer surface away fromthe slit starting point, wherein the distances from said slit startingpoint to each of the two slit terminating points are about equal. In afurther embodiment, the at least one slit terminating point is coupledwith a small circular hole for even stress release, especially when theslit tubular element is bent in one direction or the opposite direction.

[0014] In a particularly preferred embodiment, the slit tubular elementof the deflectable, high torque transmission assembly is embedded withinan elastic membrane, is covered on an inner side of the slit tubularelement, or is covered on an outer side of the slit tubular element byan elastic membrane. In one embodiment, the elastic membrane is toseparate the interior lumen of the slit tubular element from an exteriorsurrounding of said slit tubular element. The elastic membrane may beselected from the group of elastic material or expandable membraneconsisting of silicone, latex, polyurethane, thermoplastic elastomersuch as Pebax brand polyether block amides, polyethylene balloon,cross-linked polyethylene balloon, permeable membrane, polyethyleneterephthalate balloon, and the like. The slit tubular element may bemade of a material selected from the group consisting of polypropylene,polysulfone, platinum, stainless steel, Nitinol, gold, silver, iridium,tungsten, and their mixture thereof

[0015] The deflectable, high torque catheter of the present inventionfurther comprises a RF energy generator and an electrical conductorsecured to said RF energy generator and said slit tubular element,wherein the electrical conductor is adapted for transmitting RF energyfrom said RF energy generator to the slit tubular element which isconstructed of a conductive material. The high torque catheter furthercomprises at least one electrode mounted on the catheter shaft that isadjacent to the slit tubular element. The at least one electrode and/orthe slit tubular element may be used for sensing, pacing, cardioversion,defibrillation and RF energy delivery.

[0016] In still another embodiment, the catheter further comprises asteering mechanism on the handle for deflecting the distal section ofthe catheter. One end of the steering wire is usually secured at saidsteering mechanism, while the other end is secured at a distal point onthe inner side of the distal shaft section; in between the two ends, thesteering wire travels through a row of anchors inside the said slittubular element for deflecting the distal portion of said flexible hightorque catheter in one specific plane. The catheter may further compriseother steering wires traveling through other rows of anchors attached tothe slit tubular element to allow deflectability in other planes. Thecatheter may further comprise a plurality of deflectable curves on thedistal tip section of the catheter shaft being provided by the steeringmechanism on the handle. By providing a steerable catheter with aplurality of multi-directional, deflectable curves, the catheter can fitthe ventricle contours appropriately. The steering mechanism is wellknown to those who are skilled in the art. However, incorporation of amulti-planar, steering mechanism into a high torque catheter of thepresent invention is unobvious.

[0017] A method for operating a deflectable, high torque catheter withina body of a patient may comprise the steps of: (a) percutaneouslyintroducing the deflectable, high torque catheter through an opening ofthe body of the patient; (b) approaching the deflectable, high torquecatheter to a target tissue of the patient by transmitting rotationaland displacement forces through the at least one shaft section of theflexible catheter shaft; and (c) positioning the deflectable, hightorque catheter at the target tissue for diagnostic and/or therapeutictissue treatment. Said deflectable, high torque catheter comprises aflexible catheter shaft having a plurality of shaft sections, wherein atleast one shaft section comprises a high torque transmission assemblyfor transmitting torque along said at least one shaft section, said hightorque transmission assembly comprising a slit tubular element that hasa plurality of rows of slits and anchors on said slit tubular elementand has sufficient torque properties and multi-directionaldeflectability ensuring that a substantial fraction of the rotational,displacement, and bending forces provided along said at least one shaftsection are translated to rotational, displacement, and bending forcesat a distal end of said shaft section.

[0018] The method and apparatus of the present invention have severalsignificant advantages over known conventional catheters or techniques,particularly the flexible and multidirectional deflecting slit tubularelement on at least one shaft section of the flexible catheter make thecatheter particularly useful in procedures for stimulating the humanheart with pacing, cardioversion, defibrillation, and/or radiofrequencyablation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Additional objects and features of the present invention willbecome more apparent and the invention itself will be best understoodfrom the following Detailed Description of Exemplary Embodiments, whenread with reference to the accompanying drawings.

[0020]FIG. 1 is an overall view of a deflectable, high torque catheterhaving a plurality of shaft sections and at least one slit tubularelement with rows of slits constructed in accordance with the principlesof the present invention.

[0021]FIG. 2 is a perspective view of a preferred slit tubular elementon a shaft section of the deflectable, high torque flexible catheter ata non-bending state.

[0022]FIG. 3 is a cross sectional end view of a preferred slit tubularelement on a shaft section of the deflectable, high torque flexiblecatheter.

[0023]FIG. 4 is a cross sectional view of a middle shaft section havinga slit tubular element at a non-bending state.

[0024]FIG. 5 is a cross sectional view of a middle shaft section havinga slit tubular element at a bending state.

[0025]FIG. 6 is a perspective view of another preferred slit tubularelement on a shaft section of the high torque flexible catheter at anon-bending state.

[0026]FIG. 7 is a perspective view of another preferred slit tubularelement on a shaft section of the high torque flexible catheter at abending state.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0027] What is shown in FIGS. 1 to 5 is a preferred embodiment of thepresent invention. FIG. 1 shows an overall view of a deflectable, hightorque catheter having a plurality of shaft sections and at least oneslit tubular element of multi-directional deflectablity and torquetransmitting assembly constructed in accordance with the principles ofthe present invention. The deflectable high torque catheter comprises aflexible catheter shaft 1 having a distal shaft section 9, a proximalshaft section 7 and a middle shaft section 8, wherein each shaft sectionhas a distal end and a proximal end, wherein each shaft section issecured to its adjacent shaft section. Said catheter shaft has a distalend 2 and a proximal end 3. A handle 4 is secured at the proximal end 3of the proximal shaft section 7. Said flexible catheter shaft 1 has atleast one lumen 11 extending between the distal end 2 of the distalshaft section 9 and the proximal end 3 of the proximal shaft section 7.

[0028] At least one shaft section 7, 8, or 9 comprises a deflectablehigh torque transmission assembly for transmitting torque along said atleast one shaft section, said deflectable high torque transmissionassembly comprising a slit tubular element 18 that has a plurality ofrows of slits 12 on said slit tubular element 18 and has sufficientdeflectabililty and torque properties ensuring that a substantialfraction of the bending, rotational and displacement forces providedalong said at least one shaft section are translated to bending,rotational and displacement forces at the distal end of said shaftsection of the flexible catheter shaft 1.

[0029] The distal shaft section may be a fixed curve type or deflectableby employing a steering mechanism 5 at the handle 4. A push-pull plunger36 is employed to deflect the distal shaft section 9 of the flexiblecatheter shaft 1. A connector 6 is secured at the proximal end of thehandle 4. At least one electrode 24 available for electrophysiology useis disposed on the distal shaft section 9. The flexible catheter mayfurther comprise a RF energy generator 23 and an electrical conductor21, 22 secured to said RF energy generator 23 and said slit tubularelement 18, 28, wherein the electrical conductor is adapted fortransmitting RF energy from said RF energy generator to the at least oneelectrode 24 or the slit tubular element 18, 28.

[0030]FIG. 2 shows a perspective view of a preferred slit tubularelement 18 on a shaft section of the deflectable high torque catheter ata non-bending state. A plurality of rows of slits 12 along with rows ofanchors 17 are created along the slit tubular element 18. The slit canbe created or arranged with respect to a longitudinal axis of said shaftsection 7, 8, or 9 as selected from the group consisting of aperpendicular slit, an angled slit, a random slit, and a combination ofthe above thereof. The row of slits 12 can be created by a laser means,a mechanical means, or other suitable means.

[0031] Each of the plurality of slits 12 has a slit starting point 13 atan outer surface 16 of the shaft section and two slit terminating points14A, 14B at the outer surface away from the slit starting point 13. Atleast one slit terminating point 14A, 14B may be coupled with a smallcircular hole as shown in FIG. 2. Said small circular hole is for stressrelease when the slit tubular element is in a deflectable state. Eachslit may penetrate through the inner surface 15 of the slit tubularelement 18. Each of the slit starting point 13, 13A, or 13B may be onthe same side, on the opposite side, or randomly on the surface of theslit tubular element 18. This is to accommodate longitudinal torquetransmission along the slit tubular element and deflectability in aplurality of directions of the distal shaft section of this flexiblecatheter.

[0032]FIG. 3 shows a cross sectional view of a preferred slit tubularelement on a shaft section of the deflectable, high torque, flexiblecatheter. Steering wires 20 run longitudinally along the said preferredslit tubular element through the anchors 17 located at various pointswithin the slit tubular element 18.

[0033]FIG. 4 shows a cross sectional view of a middle shaft sectionhaving a preferred slit tubular element of FIG. 2 at a non-bendingstate. A distal end of the proximal shaft section 7 is firmly secured toa proximal end of a middle shaft section 8 at a joint region 19A.Similarly, a proximal end of the distal shaft section 9 is firmlysecured to a distal end of a middle section 8 at a joint region 19B. Thetwo sections can generally be secured together by adhesion, welding,screwing or other suitable means. An electrical conductor 21, 22 passedthrough the lumen 11 of the flexible catheter 1 is adapted fortransmitting electrical signal, energy, to and from an electrode meansto an external electrical equipment for signal sensing, pacing,cardioversion, defibrillation or RF energy delivery. FIG. 5 shows across sectional view of a shaft section having a slit tubular element 18of FIG. 4 at a bending or deflection state.

[0034]FIG. 6 shows a perspective view of another preferred slit tubularelement on a shaft section of the deflectable, high torque flexiblecatheter at a non-bending state. At least one shaft section 7, 8, 9comprises a deflectable, high torque transmission assembly fortransmitting bending and torque along the at least one shaft section.The deflectable, high torque transmission assembly comprises a slittubular element 28 that has at least one continuously spiraling slit 39on said slit tubular element 28 and has sufficient deflectable andtorque properties ensuring that a substantial fraction of the bending,rotational and displacement forces provided along the at least one shaftsection are translated to bending, rotational and displacement forces atthe distal end of the shaft section of the flexible catheter shaft,wherein the slit tubular element has a plurality of parallel slitmembers such as pairs of 40A-40B or 40B-40C, resulting from the at leastone continuously spiraling slit 39. In one embodiment, at least aportion 41 of at least one pair of adjacent slit members 40A-40B issecured together.

[0035] In a preferred embodiment, the slit tubular element 18, 28 of thedeflectable, high torque transmission assembly may be embedded within anelastic membrane, covered on an inner side of the slit tubular element,or covered on an outer side of the slit tubular element by an elasticmembrane. In one further embodiment, the elastic membrane is to separatethe interior lumen 11 of the slit tubular element 18, 28 from anexterior surrounding of the slit tubular element. The elastic membranemay preferably be selected from the group of elastic material,inflatable balloon, or expandable membrane consisting of silicone,latex, polyurethane, thermoplastic elastomer such as Pebax brandpolyether block amides, polyethylene balloon, cross-linked polyethyleneballoon, permeable membrane, polyethylene terephthalate balloon, and thelike. The slit tubular element 18, 28 may be made of a material selectedfrom the group consisting of polypropylene, polysulfone, platinum,stainless steel, Nitinol, gold, silver, iridium, tungsten, and theirmixture thereof

[0036]FIG. 7 is a perspective view of another preferred slit tubularelement on a shaft section of the deflectable, high torque flexiblecatheter of FIG. 6 at a bending or deflection state. Depending on whichsteering wire 20 is activated, the bending plane can differ. The slittubular element 18 can only subject to the bending force ordeflectability in the same direction of the slit 12 from the slitstaring point 13 to the slit terminating points 14A, 14B. In the case ofa slit tubular element 28 comprising a continuously spiraling slit 39, aplurality of securing portions or points 41 will make the slit tubularelement 28 subject to the bending or deflection at a direction or aplane least resistance to restriction of the secured portion or portions41.

[0037] From the foregoing, it should now be appreciated that an improvedflexible catheter having deflectable, high torque transmittingproperties has been disclosed for cardiac and cardiovascular procedures.Particularly, the slit tubular element portion of the deflectable, hightorque flexible catheter is coupled with an electrical conductor for usein stimulating the human heart with pacing, cardioversion,defibrillation, and/or radiofrequency ablation therapy. While theinvention has been described with reference to a specific embodiment,the description is illustrative of the invention and is not to beconstrued as limiting the invention. Various modifications andapplications may occur to those skilled in the art without departingfrom the true spirit and scope of the invention as described by theappended claims.

What is claimed is:
 1. A deflectable, high torque catheter comprising: aflexible catheter shaft having a distal shaft section, a proximal shaftsection and a middle shaft section, wherein each shaft section has adistal end and a proximal end, said flexible catheter shaft having atleast one lumen extending between the distal end of the distal shaftsection and the proximal end of the proximal shaft section; a handlesecured at the proximal end of the proximal shaft section; and at leastone shaft section comprising a deflectable, high torque transmissionassembly for transmitting bending and torque properties along said atleast one shaft section, said deflectable, high torque transmissionassembly comprising a slit tubular element that has a plurality of slitson said slit tubular element, wherein arrangement of said plurality ofslits with respect to a longitudinal axis of said shaft section isselected from the group consisting of an angled slit, and a combinationof a perpendicular slit and an angled slit, wherein said plurality ofslits with respect to a longitudinal axis of said shaft section arearranged in a plurality of rows parallel and staggered with respect toeach other.
 2. The deflectable, high torque catheter of claim 1 ,wherein each of the plurality of slits has a slit starting point at anouter surface of said shaft section and two slit terminating points atsaid outer surface away from the slit starting point, each slitterminating point being coupled with a small circular hole.
 3. Thedeflectable, high torque catheter of claim 1 , wherein the slit tubularelement of the deflectable, high torque transmission assembly isembedded within an elastic membrane.
 4. The deflectable, high torquecatheter of claim 1 , wherein the slit tubular element of thedeflectable, high torque transmission assembly is covered on an externalside or on an internal side of said slit tubular element by an elasticmembrane.
 5. The deflectable, high torque catheter of claim 1 , whereinthe tubular element of the deflectable, high torque transmissionassembly contains rows of longitudinal anchors acting as channels forsteering wires to deflect said slit tubular element in differentdirections.
 6. The deflectable, high torque catheter of claim 3 ,wherein the elastic membrane is selected from the group consisting ofsilicone, latex, polyurethane, thermoplastic elastomer, polyethyleneballoon, cross-linked polyethylene balloon, permeable membrane, andpolyethylene terephthalate balloon.
 7. The deflectable, high torquecatheter as in claim 1 , wherein the slit tubular element is made of amaterial selected from the group consisting of platinum, stainlesssteel, nitinol, gold, silver, iridium, tungsten, and an alloy of theirmixture.
 8. The deflectable, high torque catheter as in claim 1 ,further comprising at least one electrode mounted on the catheter shaftthat is adjacent to the slit tubular element.
 9. The deflectable, hightorque catheter as in claim 8 , further comprising a RF energy generatorand an electrical conductor secured to said RF energy generator and saidslit tubular element, wherein the electrical conductor is adapted fortransmitting RF energy from said RF energy generator to the at least oneelectrode or the slit tubular element.
 10. The deflectable, high torquecatheter as in claim 1 , further comprising a steering mechanism on thehandle for deflecting the distal shaft section of the flexible cathetershaft.
 11. A deflectable, high torque catheter comprising: a flexiblecatheter shaft having a distal shaft section, a proximal shaft sectionand a middle shaft section, wherein each section has a distal end and aproximal end, said flexible catheter shaft having at least one lumenextending between the distal end of the distal shaft section and theproximal end of the proximal shaft section; a handle secured at theproximal end of the proximal shaft section; and at least one shaftsection comprising a deflectable, high torque transmission assembly fortransmitting bending and torque properties along said at least one shaftsection, said high torque transmission assembly comprising a slittubular element that has at least one continuously spiraling slit onsaid slit tubular element and has sufficient bending and torqueproperties ensuring that a substantial fraction of the bending,rotational and displacement forces provided along said at least oneshaft section are translated to bending, rotational and displacementforces at the distal end of said shaft section of the flexible cathetershaft, wherein the slit tubular element has a plurality of parallel slitmembers resulting from the at least one continuously spiraling slit,wherein at least a portion of at least one pair of adjacent slit membersis secured together, wherein said tubular element has rows oflongitudinal anchors acting as channels for steering wires to deflectsaid slit tubular element in different directions.
 12. The deflectable,high torque catheter of claim 11 , wherein the slit tubular element ofthe deflectable, high torque transmission assembly is embedded within anelastic membrane.
 13. The deflectable, high torque catheter of claim 11, wherein the slit tubular element of the deflectable, high torquetransmission assembly is covered by an elastic membrane, the elasticmembrane separating an exterior of said slit tubular element from aninterior of said slit tubular element.
 14. The deflectable, high torquecatheter of claim 12 , wherein the elastic membrane is selected from thegroup consisting of silicone, latex, polyurethane, polyethylene balloon,cross-linked polyethylene balloon, permeable membrane, and polyethyleneterephthalate balloon.
 15. The deflectable, high torque catheter as inclaim 11 , wherein the slit tubular element is made of a materialselected from the group consisting of platinum, stainless steel,Nitinol, gold, silver, iridium, tungsten, and their mixture thereof. 16.The deflectable, high torque catheter as in claim 11 , furthercomprising at least one electrode mounted on the flexible catheter shaftthat is adjacent to the slit tubular element.
 17. The deflectable, hightorque catheter as in claim 16 , further comprising a RF energygenerator and an electrical conductor secured to said RF energygenerator and said slit tubular element, wherein the electricalconductor is adapted for transmitting RF energy from said RF energygenerator to the at least one electrode or the slit tubular element. 18.The deflectable, high torque catheter as in claim 11 , furthercomprising a steering mechanism on the handle for deflecting the distalshaft section of the flexible catheter shaft.
 19. A method for operatinga deflectable, high torque catheter within a body of a patient, thedeflectable, high torque catheter comprising a flexible catheter shafthaving a plurality of shaft sections, wherein at least one shaft sectioncomprises a deflectable, high torque transmission assembly fortransmitting bending and torque properties along said at least one shaftsection, said deflectable, high torque transmission assembly comprisinga slit tubular element that has a plurality of slits on said slittubular element, wherein arrangement of said plurality of slits withrespect to a longitudinal axis of said shaft section is selected fromthe group consisting of an angled slit, a curved slit, and a combinationof a perpendicular slit and an angled slit, wherein said plurality ofslits with respect to a longitudinal axis of said shaft section arearranged in a plurality of rows parallel and staggered with respect toeach other, wherein said tubular element has rows of longitudinalanchors acting as channels for steering wires to deflect said slittubular element in different directions; the method comprising the stepsof: (a) percutaneously introducing the deflectable, high torque catheterthrough an opening of the body of the patient; (b) approaching thedeflectable, high torque catheter to a target tissue of the patient bytransmitting bending, rotational and displacement forces through the atleast one shaft section of the flexible catheter shaft; and (c)positioning the deflectable, high torque catheter at the target tissuefor diagnostic and/or therapeutic tissue treatment.